1. Field of the Invention
The present invention relates to a dental, dental-medical or dental-technical handpiece in, which has an electric motor for driving a tool held by a tool receiver of the handpiece, in particular a dental drill.
2. Related Technology
Dental or dental-medical handpieces normally include an instrument section for receiving a rotating dental tool, for example a drill, a drive motor for driving the dental tool, and a hose section with a media delivery hose for delivering certain supply media for the operation of the handpiece. Hereunder there fall for example current for operating an electric motor and/or a light source, but also cooling media such as air and water.
FIGS. 11 and 12 show handpieces in accordance with the state of the art which are configured in different manners. As FIG. 11 shows, an instrument section 101, a drive motor 103 and a hose section 102 with a media delivery hose 104 can be configured as individual components which can then be coupled directly behind one another by plugging on. This construction thus has three coupling points between the instrument section 101 and the hose section 102, and respectively between the drive motor 103 and the two sections 101 and 102. Such a construction for a handpiece is known for example from DE 28 34 099 C2 or EP 0 012 871 B1.
A form of construction alternative to this for a dental or dental-medical handpiece is illustrated in FIG. 12. A drive motor 203 is now a so-called motor cartridge which is kept in a cavity formed by an instrument section 201 and a hose section 202. The instrument section has for this purpose a housing overlapping the drive motor 203 with integrated supply lines for receiving the supply media delivered by the media delivery hose, wherein the housing and the supply lines of the instrument section 201 are led up to the hose section 202.
These two known forms of construction are problematic in multiple regards. Thus for example, due to the great structural length, dictated by the form of construction, and the relatively great weight of the dental handpiece, handling is made more difficult since the center of gravity is shifted towards the hose side. However, delicate and easy handling is required precisely for dental work. Further, the many coupling points or separation points between the components of the handpiece are critical with regard to hygiene requirements.
To avoid these issues, correspondingly a new concept has been proposed in EP 0 888 091 A1, in which both the handpiece and the motor are divided into two components. A first section of the handpiece thereby serves for receiving a dental tool and is releasably couplable with a second section to which a medium supply line for the supply of certain supply media for operation of the tool can be connected. In turn the drive motor is divided into a rotating region and a static region with a stator winding, wherein both parts are so respectively arranged in the two sections of the handpiece that through assembly of the first and second handpiece sections the static region of the drive motor with the stator winding is pushed over the rotating region of the drive motor. In this way on the one hand the structural length of the handpiece and on the other hand the number of interfaces can be reduced in comparison with the concepts illustrated in FIGS. 11 and 12.